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 A187402 Number of (n+1)X(n+1) 0..2 arrays with diagonal zero and the i,j-th 2X2 subblock sum equal to the j,i-th 2X2 subblock sum 0
 9, 141, 4743, 378999, 77470101, 43182942669, 69704886620367, 343603587128867631, 5351921330163734358189, 265547472520415711196418101 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 2 of A187408 LINKS EXAMPLE Some solutions for 4X4 ..0..0..2..1....0..2..0..0....0..2..0..1....0..2..0..2....0..2..0..2 ..2..0..2..0....1..0..0..2....2..0..2..0....2..0..1..1....2..0..2..0 ..0..2..0..2....0..1..0..1....2..0..0..0....0..1..0..1....0..2..0..1 ..2..1..1..0....1..0..2..0....1..0..2..0....2..1..1..0....2..0..1..0 CROSSREFS Sequence in context: A137059 A263966 A083084 * A303147 A317354 A050787 Adjacent sequences:  A187399 A187400 A187401 * A187403 A187404 A187405 KEYWORD nonn AUTHOR R. H. Hardin Mar 09 2011 STATUS approved

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Last modified October 20 10:00 EDT 2020. Contains 337900 sequences. (Running on oeis4.)